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Chapter II <br /> As recommended by Golder & Assoc. in reviewing the Phase II sediment pond <br /> designs, special care is taken with the cleaning and maintenance of the Sutey area <br /> ponds and appurtenant structures. <br /> (4) Sutey - Reclamation. <br /> Permanent slopes of the pile will be reclaimed by final grading, topsoil placement <br /> and revegetation. <br /> Varying depths of topsoil will be distributed on the permanent slopes, placed <br /> according to aspect, with 12-18 inches on north and east slopes, 18 to 24 inches on <br /> west and 24 to 30 inches on the south slopes. <br /> Seeding and planting of permanent slopes will be done during the first normal <br /> period for favorable planting (normally late fall --October and November). The <br /> special Sutey mix will be broadcast seeded at 30 Ibs/acre. <br /> Suitable mulch and/or other soil stabilizing practices will be used promptly, with <br /> straw mulch broadcast at 1-1/2 to 2 tons per acre on all regraded and topsoiled <br /> areas to reduce erosion and promote germination of seeds. <br /> b. Old Pile. <br /> From 1961 until late in 1984 coal refuse was deposited at a site just east of the <br /> preparation plant and adjacent to Coal Creek. By the time it was closed in 1984, <br /> approximately 2 million cubic yards of coal waste had been deposited at this site, <br /> with a maximum height of approximately 180'. <br /> An extensive study of the facility was done in 1977 by Morrison-Knudsen. Another <br /> was done in 1984, last year during which it was in active use, by Geo-Hydro (see <br /> App. II-B-7). <br /> As noted in these studies, characteristics of the refuse pile and construction include: <br /> — The M-K study evaluated the coal refuse and its <br /> physical properties, and a series of stability analyses <br /> was performed to verify the stability of the existing <br /> piles and to estimate the stability of the future facility <br /> extensions or the stability of a new facility. <br /> — The coal refuse material can be classified as <br /> well-graded, silty gravel (GM) in accordance with the <br /> Unified Soil Classification System. <br /> 42 <br />